spinous process of a vertebra
Webster's Dictionary (GCIDE)
Spinous \Spi"nous\, a.
1.Spinose; thorny. [1913 Webster]
2.Having the form of a spine or thorn; spinelike. [1913 Webster]
Spinous process of a vertebra (Anat.), the dorsal process of the neural arch of a vertebra; a neurapophysis. [1913 Webster]